Electron capture and loss in the scattering of H~+ from HOPG graphite

摘要

In this paper we report measurements of the positive (H~+) and negative (H~-) ion fractions after H~+ scattering from a highly oriented pyrolytic graphite (HOPG) surface. The experimental results show that for a fixed (large) exit angle the negative fraction is almost independent of the primary ion energy, while the positive fraction increases steadily. For a fixed incident energy, the H~+ and H~- fractions show a complementary behavior with exit angle. A dynamical quantum mechanical calculation, based on the localized and extended features of the atom-surface interaction, allows us to understand many of the features of the experimental results.